Endotracheal intubation is a very common medical procedure by which a flexible plastic endotracheal breathing tube is inserted into a patient's trachea for providing oxygen or anesthetic gases to the lungs. Usually, the endotracheal tube is introduced into the patient's trachea after the patient has been sedated or has become unconscious. Typically, the patient is placed on his or her back, and the patient's chin is lifted in order to place the patient in the so-called "sniffing" position. When the head and neck of the patient are situated to achieve the proper position, the patient's tongue typically falls downward toward the roof of the patient's mouth. The endotracheal tube must be inserted past the patient's teeth and tongue and further past the epiglottis and vocal cords into the trachea. After the endotracheal tube is advanced past the vocal cords and into the patient's trachea, the distal end of the tube should be approximately 2 to 4 centimeters (about 1 to 2 inches) in front of the bifurcation of the trachea in order to ventilate both of the patient's lungs equally.
A tracheostomy is another procedure by which a breathing tube is placed into a patient's trachea for providing oxygen or anesthetic gases to the lungs. An incision is made in the base of the patient's neck above the sternum so that a tracheostomy tube can be inserted into the patient's trachea.
In addition to proper initial placement of a breathing tube, which very often is done under emergency conditions, it is desirable to change a patient's endotracheal or tracheostomy tube approximately weekly to prevent harmful reaction from long-term intubation such as granulation tissue reaction, infection, or stenosis of the trachea, larynx, or subglottis.
In some cases, the placement of the tube is made difficult due to trauma or physical differences in the tracheal areas of different patients. Patients differ in size, age, and sex. In some cases, incorrect placement of the breathing tube may injure the patient. The tube must be placed so that it can deliver oxygen or anesthetic gas to both lungs. Serious complications may result if the tube is placed incorrectly, such as into the esophagus or into only one bronchus. With an endoscopic intubation assist device, the practitioner can view the patient's tracheal area and is able to more accurately place the tube. Existing devices, however, are not adjustable for different size patients that require various sizes of endotracheal or tracheotomy tubes.
One attempt to solve that problem is a device commonly referred to as a "laryngoscope" which is often used to move and hold the patient's tongue to permit viewing of the throat and tracheal area of the patient. Examples of laryngoscopes are disclosed in Bartlett, U.S. Pat. No. 4,947,896 entitled "Laryngoscope," and in May, U.S. Pat. No. 4,126,127, entitled "Suctioning/Oxygenating Laryngoscope Blade." A laryngoscope that incorporates fiber optics for viewing and illuminating the region around the patient's larynx is disclosed in Wu, U.S. Pat. No. 4,982,729 entitled "Rigid Fiberoptic Intubating Laryngoscope."
The common laryngoscope is somewhat of a misnomer as it is actually a combination tongue depressor and flashlight. It does not actually provide an endoscopic view of the internal anatomy. The laryngoscope is used to facilitate endotracheal intubation by forming a passageway past the patient's tongue and teeth so that the endotracheal tube can be inserted into the trachea. The practitioner must still rely on tactile feel and experience to make certain that the tube is correctly placed.
Another device that is used to assist intubation is an elongated wire or stylet made of malleable material which can be bent or shaped to accommodate a particular patient. The malleable stylet is inserted into the endotracheal tube and then used to guide the tube into place within the patient's tracheal passage. The stylet is then removed, and the tube is connected to a supply conduit which then supplies the oxygen or other gas to the lungs of the patient. In the normal practice of endotracheal intubation procedures, the medical practitioner pre-shapes a 3 to 4 mm outside diameter aluminum stylet over which the endotracheal tube is placed and then follows a blind approach to accomplish intubation.
More recent devices, however, have incorporated fiber optics to provide an endoscopic view of the tracheal area into which an endotracheal tube is to be inserted. The fiber optics are usually incorporated into the stylet which is used to guide the tube into place. Examples of intubation assist devices which incorporate fiber optics are disclosed in Adair, U.S. Pat. No. 5,329,940 entitled "Endotracheal Tube Intubation Assist Device;" Salerno, U.S. Pat. No. 5,337,735 entitled "Fiber-Lighted Stylet;" Berci, U.S. Pat. No. 4,846,153 entitled "Intubating Video Endoscope;" and Zukowski, U.S. Pat. No. 3,677,262 entitled "Surgical Instrument Illuminating Endotracheal Tube Inserter."
While these devices provide some viewing, they can be used with an endotracheal tube of only one length or a limited range of lengths within a particular category such as pediatric or adult. Also, many of these devices are relatively complicated in that they may include a suction port, oxygen or gas supplying means, gas flow directed means, or other control systems.
Other prior art devices are simply a handle with a light source from which extends an encased malleable fiber-optic cable which transmits light to the local area to be viewed. These devices resemble a flashlight with a fiber-optic cable at the end that carries light into the trachea of a patient in order to illuminate the area into which an intubation tube is to be placed. These devices, however, do not transmit an image and are of a fixed length.
Still other devices are simply a rigid tube within which is carried a fiber-optic cable and onto which is sleeved the endotracheal tube to be inserted into the patient. These do not provide a way to adjust for endotracheal tubes of varying lengths or even to adjust for differences in the size or anatomy of the patient.
The prior art patents described all disclose fixed length endoscopes that can only be used with endotracheal tubes of only one length or of a limited range of lengths. These devices necessitate different versions for the many available endotracheal tubes from pediatric to adult sizes. Also, prior art devices that use fiber optics are relatively expensive and complex and therefore are not used very often because of the high cost of operating and maintaining these devices. The cost of repairing or replacing one of these units is very high compared to that of the present invention.
A need exists in the art for an intubation assist device that allows the medical practitioner to view the tracheal area during the procedure. It would also be beneficial to be able to use one size of endoscopic viewing system with several sizes of endotracheal tubes such as from pediatric to adult sizes. The device also should be simple, inexpensive, and easy to use. The present invention meets these desires.